Pulp, Paper, Sugar and Ethanol - Chemical Technology - Chemical Engineering Previous Year Questions

1

2007 · Chemical Engineering · Chemical Technology · Pulp, Paper, Sugar and Ethanol

Chemical Engineering (CH) 2007

In the Sulfite process for paper manufacture, the ‘cooking liquor’ is

A

magnesium bisulfite and sulfur dioxide in acid medium

B

magnesium sulfite and magnesium dicarbonate

C

sodium sulfite and magnesium sulfite

D

sodium sulfite, sodium bisulfite and sulfur dioxide

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2

2008 · Chemical Engineering · Chemical Technology · Pulp, Paper, Sugar and Ethanol

Chemical Engineering (CH) 2008

Which ONE of the following process sequences is used in the sugar industry?

A

Ca₃HPO₄/ Lime Treatment → Crystallization → Crushing

B

Ca₃HPO₄/ Lime Treatment → Multiple stage evaporation → Crystallization

C

Crushing → Crystallization → Ca₃HPO₄/ Lime Treatment

D

Multiple stage evaporation → Crystallization → Ca₃HPO₄/ Lime Treatment

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3

2016 · Chemical Engineering · Chemical Technology · Pulp, Paper, Sugar and Ethanol

Chemical Engineering (CH) 2016

Two paper pulp plants P and Q use the same quality of bamboo as a raw material. The chemicals used in their digester are as follows:

	Plant P	Plant Q
NaOH	Yes	No
Na2S	Yes	No
Na2CO3	Yes	Yes
NaHCO3	No	Yes
Na2SO3	No	Yes

Which one of the following statements is CORRECT?

A

Plant P and Plant Q both use the Sulfite process

B

Plant P and Plant Q both use the Kraft process

C

Plant P uses Sulfite process

D

Plant P uses Kraft process

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4

2018 · Chemical Engineering · Chemical Technology · Pulp, Paper, Sugar and Ethanol

Chemical Engineering (CH) 2018

The molecular formula of the predominant chemical compound in commercial sugar is

A

C_{12}H_{22}O_{11}

B

C_{12}H_{24}O_{12}

C

C_{6}H_{10}O_{5}

D

C_{6}H_{12}O_{6}

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5

2019 · Chemical Engineering · Chemical Technology · Pulp, Paper, Sugar and Ethanol

Chemical Engineering (CH) 2019

In Kraft process, the essential chemical reagents used in the digester are

A

caustic soda, mercaptans and ethylene oxide

B

caustic soda, sodium sulphide and soda ash

C

quick lime, salt cake and dimethyl sulphide

D

baking soda, sodium sulphide and mercaptans

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6

2022 · Chemical Engineering · Chemical Technology · Pulp, Paper, Sugar and Ethanol

Chemical Engineering (CH) 2022

In soap manufacturing, the triglycerides present in oils and fats are hydrolyzed to mainly produce

A

Fatty acids and glycerol

B

Glycerol only

C

Fatty acids only

D

Glycerol and paraffins

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7

2022 · Chemical Engineering · Chemical Technology · Pulp, Paper, Sugar and Ethanol

Chemical Engineering (CH) 2022

The chemical formula of Glauber's salt, used in the Kraft process, is

A

Na₂CO₃.10H₂O

B

Na₂S₂O₃.2H₂O

C

Na₂HPO₄.2H₂O

D

Na₂SO₄.10H₂O

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8

2025 · Chemical Engineering · Chemical Technology · Pulp, Paper, Sugar and Ethanol

Chemical Engineering (CH) 2025

To manufacture paper from __(i)__, the __(ii)__ must be freed from the binding matrix of __(iii)__ in the pulping step.
Which one of the following is the CORRECT option to fill in the gaps (i), (ii) and (iii)?

A

(i) wood, (ii) cellulose fibers, (iii) lignin

B

(i) lignin, (ii) cellulose fibers, (iii) wood

C

(i) lignin, (ii) wood, (iii) cellulose fibers

D

(i) wood, (ii) lignin, (iii) cellulose fibers

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9

2026 · Chemical Engineering · Chemical Technology · Pulp, Paper, Sugar and Ethanol

Chemical Engineering (CH) 2026

In a traditional continuous Kraft (Sulfate) pulping process, consider the following major steps:
Bleaching (BL), Chipping (CH), Debarking (DE), Digestion (DI), and Pulp Washing (WA).
Which one of the following is the CORRECT sequence of steps for this process?

A

DE → BL → WA → DI → CH

B

DE → CH → DI → WA → BL

C

DE → CH → WA → DI → BL

D

DE → BL → WA → CH → DI

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